The most widely used method within the province of the invention is represented by the corn picker heads mounted on the different combines. The construction of nearly all corn picker heads known has been similar. Gathering chains, snapping strips and gathering rolls are arranged along parallel rows, and driven through an angular gear box in each row. The crop is transported by an auger or sloping elevator.
The FKA-type corn picker heads can be provided also with stalk swather adapter consisting of left and right-side units mounted below the adapter, provided with an alternately moving mower assembly and console-type pair of augers.
Also known are the gathering auger adapters suitable for the harvesting of sunflowers. Here the crop is transported by augers driven through angular gear boxes rotating at high peripheral speed along the length of the rows parallel to the cutting auger at the inside end of the augers, then to the gathering auger and sloping elevator.
The unfavorable properties of the known methods are characterized in that apart from being single-purpose units, their construction is complicated, the gross weight, power requirement and capital cost are high, and they do not allow the harvesting of the stalk.
The above described drawbacks are even more valid for the corn picker head fitted with a stalk swather which allows the harvesting of the stalks but is functionally sensitive to the condition of the crop and reduce the capacity of the machine.
The NA-type assemblies (bucket elevators, reel, shield, etc.) of the harvesting part of the different combine harvesters are generally used for sunflower harvesting.
Also known are the corn picker heads suitable for the harvesting of sunflowers with the aid of cutter assemblies at the ends of the gathering rolls. One such four-row adapter is described in the French patent specification No. 242 63 97.
These units are disadvantageous in that the number of the harvested rows depends on the corn picker head because of, their complex construction and their gross weight, and because the reel and the gathering rolls result in inefficient operation and do not allow the harvesting of the stalks.
There are different parallel arranged direct cut headers connected through a gathering auger to the basic machine, as well as converging adapters directly connected to the basic machine suitable for the harvesting of soya and silage corn. Apart from being mainly single-purpose units, these machines are expensive and do not allow economical mass production.
The appearance of high capacity combines and forage harvesters including their suitability for several technological processes necessitated the development of a large number of multi-purpose adapters, which meet agrotechnical requirements, and allow the harvesting of the stalks as a by-product. The proper utilization of the high capacity machines can be ensured only this way in accord with the possibilities and requirements of the large-scale farming, which require the economic production of the mass-produced, extensively standardized adapters.